Hashcat with md5 and Mask

Hashcat with md5 and Mask

I'm trying to connect to my meter by using some open-source software, all the meter supports the dlms-cosem standard. But the problem is the meter disconnected due to a failed security check.

After some research about the issue, I found the encryption method:

data(F [ StoC] = MD5[ StoC || Hls-secret]). 

The meter is disconnecting because of the wrong value HLS-secret set by open-source software.

So, I wanted to find this parameter by using hashcat to retrieve it from the plaintext of F [ StoC ].

After I sniff the communication between the manufacturer software and the meter, I managed to get:

StoC: 852F8855BBD04A34F2710D132813D071 
F[StoC]: C7E7A14A19ECFC56C3BC9636BF950AC1

from these parameters, how can I get the HLS-secret with hashcat?